package cn.bo.cloud.common.core.utils.image;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import javax.imageio.ImageIO;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.*;

/**
 * @ClassName RotateImage
 * @Description TODO
 * @Author jb.zhou
 * @Date 2020/12/30
 * @Version 1.0
 */
public class RotateImage {
    private static final Logger logger = LoggerFactory.getLogger(RotateImage.class);

    public static void toRotate(File in, int angel, String outPath) throws IOException {
        String fileName = in.getName();
        String suff = fileName.substring(fileName.lastIndexOf(".")+1);
        BufferedImage src = ImageIO.read(in);
        BufferedImage des = RotateImage.Rotate(src, angel);
        ImageIO.write(des, suff, new File(outPath));
    }

    public static InputStream toRotate(InputStream in, int angel, String suff) throws IOException {
        BufferedImage src = ImageIO.read(in);
        BufferedImage des = RotateImage.Rotate(src, angel);
        return bufferedImageToInputStream(des,suff);
    }

    public static BufferedImage Rotate(Image src, int angel) {
        int src_width = src.getWidth(null);
        int src_height = src.getHeight(null);
        // calculate the new image size
        Rectangle rect_des = CalcRotatedSize(new Rectangle(new Dimension(
                src_width, src_height)), angel);

        BufferedImage res = null;
        res = new BufferedImage(rect_des.width, rect_des.height,
                BufferedImage.TYPE_INT_RGB);
        Graphics2D g2 = res.createGraphics();
        // transform
        g2.translate((rect_des.width - src_width) / 2,
                (rect_des.height - src_height) / 2);
        g2.rotate(Math.toRadians(angel), src_width / 2, src_height / 2);

        g2.drawImage(src, null, null);
        return res;
    }

    public static Rectangle CalcRotatedSize(Rectangle src, int angel) {
        // if angel is greater than 90 degree, we need to do some conversion
        if (angel >= 90) {
            if(angel / 90 % 2 == 1){
                int temp = src.height;
                src.height = src.width;
                src.width = temp;
            }
            angel = angel % 90;
        }

        double r = Math.sqrt(src.height * src.height + src.width * src.width) / 2;
        double len = 2 * Math.sin(Math.toRadians(angel) / 2) * r;
        double angel_alpha = (Math.PI - Math.toRadians(angel)) / 2;
        double angel_dalta_width = Math.atan((double) src.height / src.width);
        double angel_dalta_height = Math.atan((double) src.width / src.height);

        int len_dalta_width = (int) (len * Math.cos(Math.PI - angel_alpha
                - angel_dalta_width));
        int len_dalta_height = (int) (len * Math.cos(Math.PI - angel_alpha
                - angel_dalta_height));
        int des_width = src.width + len_dalta_width * 2;
        int des_height = src.height + len_dalta_height * 2;
        return new Rectangle(new Dimension(des_width, des_height));
    }
    /**
     * 将BufferedImage转换为InputStream
     * @param image
     * @param suff 后缀
     * @return
     */
    public static InputStream bufferedImageToInputStream(BufferedImage image, String suff){

        try (ByteArrayOutputStream os = new ByteArrayOutputStream()){
//            ImageIO.write(image, "png", os);
            ImageIO.write(image, suff, os);
            InputStream input = new ByteArrayInputStream(os.toByteArray());
            return input;
        } catch (IOException e) {
            logger.error("提示:{}",e);
        }
        return null;
    }

}
